Using "the"...

I believe both of the following sentences are correct. But what is the difference if I use "the" or not...?

1. Mr. Smith plays violin.

2. Mr. Smith plays the violin.

I seem to recall that if you play violin, you play in a group (orchestra, quartet, etc.). If you play THE violin, you generally play solo (or with a piano accompaniment).

Or does this make absolutely no difference?